Nacelles for jet engines may include a pre-cooler inlet duct that may direct a pre-cooler air stream onto a heat exchanger assembly to cool engine bleed air prior to it being utilized by the jet engine and/or by another component of an aircraft that includes the jet engine. The pre-cooler inlet duct may be present within the nacelle and may be located to receive a portion of a compressed air stream that may be pressurized by a compressor of the jet engine.
Because the pre-cooler inlet is located within the nacelle, a size of the pre-cooler inlet may be restricted by a size of the nacelle. Conversely, a given size pre-cooler inlet may dictate a needed size for a nacelle that may contain the pre-cooler inlet. In addition, a desired flow rate of the pre-cooler air stream also may dictate a needed size for the pre-cooler inlet duct.
Under certain conditions, it may be desirable to increase the flow rate of the pre-cooler air stream without increasing the size of the pre-cooler inlet duct. Additionally or alternatively, it also may be desirable to decrease the size of the pre-cooler inlet duct, such as to permit the pre-cooler inlet duct to be placed within a smaller nacelle and/or to decrease a portion of the interior of the nacelle that is utilized by the pre-cooler inlet duct, without decreasing the flow rate of the pre-cooler air stream.
Historically, traditional aerodynamic principles have been utilized to design the size and/or shape of the pre-cooler inlet duct. However, these traditional aerodynamic principles may limit the size and/or shape of the pre-cooler inlet, thereby restricting increases in the flow rate of the pre-cooler air stream and/or decreases in the size of the nacelle. It is with such considerations in mind that examples according to the present disclosure are described in further detail below.